Device for laying out structural work



F.'B. MCKINNEY.

DEVICE FOR LAYING OUT STRUCTURAL WORK.

APPLICATION FILED JAN. 28. 1920.

1,367,612. Patented Feb'.8,1921.'

UNITED STATES PATENT QFFICE.

FRANCIS B. MCKINNEY, O BALDWIN TOWNSHIP, ALLEGHENY COUNTY, PENNSYL- VANIA, ASSIGNOR 0F ONE-HALF TO JOHN H. POAGUE, OF PITTSBURGH, PENN- SYL'V'ANIA.

DEVICE FOR LAYING OUT STRUCTURAL W'ORK.

Application filed January 28, 1920.

f '0 all w ham it may concern 1 Be it known that I, FRANCIS l5. McKin- NEY, a citizen of the United States, and a resident of Baldwin township, in the county of Allegheny and State of Pennsylvania, have made a new and useful Invention in Devices for Laying Out Structural lVorlr, of which the following is a specification.

The invention relates to devices for laying out structural work and is designed primarily to lessen the labor incident to ob twining certain dimensions by the more or less tedious operation of placing the work upon a drawing board. One embodiment of the. invention and its method of use is illustrated. in the accompanying drawings wherein.

Figure l is a plan view of the apparatus in one position of use. Figs. 2 and 3 are sections on the lines IIII and III- III of Fig. 1, and Fig. at is a diagrammatic view illustrating one concrete problem which may be solved by the use of the device.

The body portion of the device consists of a face plate 1 of wood or metal stiffened and supported by frame work 2 whose inner edges are indicated by the dotted lines 3 in Fig. 1, such frame work being made of wood or other suitable material. The face plate is graduated around its edges as illustrated, the vertical line l constituting the starting point of the horizontal graduations 5 and the horizontal line 6 constituting the starting point of the vertical graduations 7 with the lines l; and 6 intersecting at S. The graduations 7 which occur at the even inches extend clear across the face plate for the purpose hereinafter indicated in the description of the operation.

Mounted in the corner of the frame work 2 is the slide block 9. The slide moved back and forth and held in any desired position by means of the screw ll) swiveled at its end in the slide block. The block is provided with a transverse center line 11 adapted to register with the graduations along the right hand side of the slide block. Pivoted at the point 12 on the slide block is the graduated. rule 13. this pivotal connection being such that the rule may be clamped against swinging movement after it is once positioned. This connection, as shown in Fig. 2, comprises a boss 14 on the under Specification of Letters Patent.

Patented Feb. 8, 19.21.

Serial No. 354,625.

side of the rule engaging a recess in the slide block and a screw 15, threaded mto the block, and engaging the washer member 16 fitting in a recess in the upper side of the rule. It will be understood that the details of construction as shown and described in volving the specific body device the method of constructing and operating the slide block and the method of pivoting and clamping the rule are unimportant in so far as the invention is concerned and may be modified to suit conditions and requirements.

The graduated edge of the rule lies on the line 17 extending through the center of the pivotal support 12 of the rule, the graduations have their genesis at this point and may be said to begin at such point although the first graduation is one inch from such point.

Mounted on the rule 13 for sliding movement longitudinally thereof is a second rule 18, such rule being graduated along one edge and such graduations beginning or having their genesis on the line 17 which constitutes the graduated edge of the rule 13.

The function and utility of the device will be most readily understood by an explanation of the solution of a concrete problem of simple character such as is constantly encountered in laying out structural work and which, while presenting no ditficulties, in the repeated operation requires in the aggregate the expenditure of much valuable time, a large part of which may be saved by the use of my device. Fig. 4': illustrates a pair of angle irons 19 and 20 forming part of a truss or other construction, such angle irons lying at an angle and requiring connection' by means of the gusset plate 21. In order to detail these three members in a working drawing it is necessary to determine the position of the rivets 22, 23, 24, 25, 26 and 27 and this requires first of all the distance marked on, the point 22 being located at the intersection of what may be termed the base lines 28 and 29 of the two angle irons upon which the rivets are to be located. With four inch angle irons such as those illustrated these lines are at the centers of the angle irons and the dis tance between the point a and the flange of the angle iron 20 is fixed by shop practice at one-half inch. Under ordinary conditions the angle Z) is not known but the lengths of the sides of the triangle of which the lines 28 and 29 constitute two sides are known and from the usual hand-books, the angle bin terms of the base and altitude of a right angled triangle is readily found.

'For the purpose of this illustration such base and altitude are assumed respectively as twelve and six inches indicated in the drawing. The factors in the design of the joint are therefore all known except the distance :12, the location of the rivet-s after this distance is known being a matter of established engineering practice.

To arrive at the distance a; in the usual way requires the laying out of the two angle irons on paper and the extension of the lower end of the angle iron 19 to such point that the point (4 lies one-half inch from the flange of the angle iron 20, after which the distance :0 may be found by measurement.

By the use of my device the distance as found as follows. The slide block 9 is first adjusted until its center line coincides with the line 6 and the rule tilted about its pivot until its edge cuts across the six inch graduation at the left of the plate 2, the position of such edge being indicated by the line 30 (Fig. 1). The rule is then clamped against swinging movement by means of the screw 15 and the slide block 7 is adjusted down a half-inch to the position illustrated in Fig. 1, such adjustment taking care of the halfinch dimension of Fig. 4 between the point a and the upper edge of the flange of the angle iron 20. The rule 18 is then adjusted along the rule 13 until its two inch graduation touches the two inch graduation T as illustrated. The distance 00 may now be found by the reading on the rule 13, such distance being indicated on the drawing. The reason for the result is obvious without further explanation, and it will be apparent that the device may be employed to solve a variety of problems which would otherwise require laying out of the parts upon paper.

IVhat I claim is:

1. In a device of the class described, a body member provided with transverse graduations extending thereacross, a rule pivoted to the body member andadapted to be positioned extending diagonally of the graduations at varying angles, means whereby the point of pivotal support of said rule maybe adjusted transversely with respect to said graduations, and a second rule mounted on the first rule for movement longitudinally thereof and extending at right angles thereto.

2. In a device of the class described, a body member provided with transverse graduations extending thereacross, a block adj acent one corner of the body member mounted mg angles, and a second rule mounted on the first rule for movement longitudinally thereof, and extending at right angles thereto.

3. In a device of the class described, a body member provided with transverse graduations extending thereacross, a graduated rule pivoted to the body member and adapted to be positioned extending diagonally of the graduations at varying angles, the graduations of the rule beginning with the point about which the rule is pivoted. and one edge thereof being in alinement with such point, means whereby the point of pivotal support of said rule may be adjusted transversely with respect to the first mentioned graduations, and a second graduated rule mounted on the first rule for movement longitudinally thereof and extending at right angles thereto, the graduations on said second rule beginning at the said edge of the first rule.

4:. In a device of the class described. a body member provided with transverse graduations extending thereacross, a block adjacent one corner of the body member mounted for adjustment in a direction transverse to said graduations, the said body member having graduations at the side of the block whereby the amount of adjustment may be determined, a rule pivoted to said block and adapted to be positioned extending diagonally of the graduatious at varying angles, and a second rule mounted on the first rule for movement longitudinally thereof and extending at right angles thereto.

In a device of the class described, a body member provided with a pair of graduated lines, at right angles to each other with the graduations having their origin at the point of intersection of said lines. a slide member mounted for adjustment on said member along one of said lines. a graduated rule pivoted on said slide member with its graduations having their origin at the pivotal point of the rule and having such pivotal point on the line along which the slide member is adjustable, a second graduated rule mounted for movement along the pivotal rule, and means for clamping the pivotal rule'to the slide member at its various positions of pivotal adjustment.

In testimony whereof,.I have hereunto subscribed my name this 17th day of Jan. 1920.

FRANCIS B. MGKINNEY. 

